import unittest


def suma(x, y):
    return x + y


def resta(a, b):
    return a - b


def multiplicacion(c, d):
    return c * d


def division(e, f):
    if f != 0:
        return e / f
    else:
        print ('No se puede dividir por 0')


class testdivision(unittest.TestCase):
    def test(self):
        self.assertEqual(division(10, -2), -5)


class testmultiplicacion(unittest.TestCase):
    def test(self):
        self.assertEqual(multiplicacion(5, 6), 30)


class testresta(unittest.TestCase):
    def test(self):
        self.assertEqual(resta(4, 7), -3)


class testsuma(unittest.TestCase):
    def test(self):
        self.assertEqual(suma(2, -3), -1)


if __name__ == '__main__':
    unittest.main()

